Staphylococcus aureus. Perhaps you had it due to a wound infection. In most cases, it goes away without treatment, but in severe cases, antibiotics that kill the bacteria may be needed. This is true for the majority of the population. In fact, many of us – even though we feel perfectly normal – carry staph in our nose, a nice moist environment in which the bacteria thrive.
However, more and more staphylococci are becoming resistant to antibiotics (also known as multi-resistant Staphylococcus aureus, or MRSA), and these infections are difficult to treat.
“Antibiotic resistance is becoming a growing problem, especially on a global scale. And when you have this relatively simple infection that suddenly cannot be treated with antibiotics, the situation can become serious, sometimes life-threatening,” says LEO’s Professor Nils Odum Foundation. Skin Immunology Research Center at the University of Copenhagen.
Therefore, many resources are being invested worldwide in the fight against antibiotic resistance in Staphylococcus aureus infections, and a new study among patients with cutaneous lymphoma has shown positive results. A new substance called endolysin has proven its ability to kill both resistant and non-resistant Staphylococcus aureus without the need for antibiotics. But we will come back to that later.
The discovery is good news for patients with weakened immune systems, for whom infection with Staphylococcus aureus can be serious and, in the worst case, fatal. But it also adds to our knowledge of other forms of treatment.
“For people who are seriously ill, for example with lymphoma of the skin, staphylococci can be a huge, sometimes insurmountable problem, as many are infected with a type of staphylococcus aureus that is resistant to antibiotics,” says Nils Odum and adds:
“That’s why we try not to give antibiotics to everyone, because we don’t want to deal with more resistant bacteria. So it’s important to find new ways to treat – and not least to prevent – these infections.”
A new substance may be the answer
In some patients, Staphylococcus aureus causes an exacerbation of cancer. And even if antibiotics seem to work in some cases, it’s not without problems.
“We can say that giving high-dose antibiotics to patients with serious infections improves their health, improves skin and cancer symptoms. But as soon as we stop giving them antibiotics, the symptoms and the staph quickly recover. Patients experience many side effects and some risk of developing resistant bacteria,” says Nils Odum.
Therefore, treating Staphylococcus aureus can be challenging. In the worst case, cancer patients can die from an infection that doctors are unable to treat.
And that’s where endolysins come in, as this new substance could be part of the solution to antibiotic resistance like MRSA.
“This particular endolysin is a completely new, artificially produced enzyme that has been improved several times and developed as a new drug,” explains Postdoc Emil Polesen, first author of the study. He adds:
“The great thing about this enzyme is that it was designed to penetrate the wall of Staphylococcus aureus. This allows it to target and kill the harmful Staphylococcus and leave the harmless skin bacteria intact.”
And this is what led the researchers to try to test the new substance; they expected it to be able to kill both resistant and non-resistant staph bacteria.
“We tested the substance on patient skin samples and it appears to kill Staphylococcus aureus in patients. Endolysin doesn’t care if the bacteria is resistant to antibiotics or not, because it doesn’t work like antibiotics, says Nils Odum and adds:
“The really good news is that our lab tests have shown that endolysins not only kill Staphylococcus aureus, but also interfere with their ability to promote cancer growth.”